Hoisting apparatus



c. T. slEBs -HOISTING APPARATUS Filed July `11 1925 2' sheets-sheet 1 Jan. 18,1927. `l;6`l4,575

. v c. T. slEBS HoIsTINo APPARATUS 2 Sheets-Sheet 2 Filed July 11 1925 l t To conmoL c/RcU/r 0F @von nevar/NG No Patented Jan. 18, 1927.

UNITED' STATES.

CLAUDE THEODORE SIEBS, OF RIVERSIDE,

l A1,614,575 PATENT oFFicE.

Immers, Assrenon To WESTERN ELEC- TRIO COMPANY, INCORPORATEIL OF NEW YORK, N. Y., .A CORPORATION OF NEW Hors'rrne APPARATUS.

Application fue@ July 11,

This invention relates to hoisting apparatusv and more particularly to electrically operated locomotive cranes and the like.

When operating hoisting apparatus, es-

' pecially electrically operated cranes of a relatively high center of' gravity design and having a long boom radius, the stability of the crane under certain working conditions V is sometimes reduced to a figure which neces- AICI sitates limiting the boom radius used under maximum load conditions or limiting the load carried under maximum boom radius conditions. Especially in the operation of hoisting apparatus of the locomotive type,

such las is movably mounted on rails, the pos'- sibility of overbalancing due to excessive loading with the boom operating in certain zones, sometimes renders its operation very unsafe unless the load or boom radius is limited to a predetermined safe figure in those zones.A l

The primary object of this invention is the provision, in hoisting apparatus of the above character, of' mechanism for insurlng its safe operation at substantially full capacity throughout its entire range of action.

One embodiment of the invention may comprise an electrically 'operated locomotive crane, such as is movably mounted on rails,

l the operation of -which may be controlled by two` electrical limit switches. connected in parallel with one another in the operating circuit. .A suitable tension device mount-ed in the boom lift operates one of the limit switches whenthe product of the weight lifted multiplied by the boom radius equals some predetermined figure. The other llimit switch is operated by a suitable platform cam in accordance with the angular position of 40 the boom with respect-to the rails. An additional inching pushbutton switch maybe. provided to enable the operator to inch back into a safe zone should he pull out .both limit switches by excessive loading. y

Other features of the invention will become apparent in the following detail description, reference being had to the accompanying drawings, wherein l Fi 1 is a schematic side view of an elec- 5 trica ly operated locomotive crane embodyin the features of the present invention;

ig. 2 'is a schematic fragmentary plan view thereof; t Y

`Figs. 3 and 4 are enlarged deta1l views of 1925. Serial No. 42,883.

one form of tension device that may be emwheels 11 whereby it is adapted to travel along a standard gauge track 12. Supported by the truck lOvis a platform 14 upon which is rotatably carried the usualV operators cab 15.. The cab 15 is supported on a plurality of rollers 16 which travelon the upper surface' of the platform 14 when the cab 15 is rotated. Rigidly supportedv by the frame of the cab is a suitable structural steel mast 18, to thelower end of whichis pivotally connected an elongated structural steel boom 19.

Mounted in the cab 15 is a suitable winding drum 20 having attached thereto and adapted to receive a cable 22 for raising and lowering alhoist block 23 carried at the outer end or head of the boom 19. One end of the cable 22 is suitably attached to the outer end of the boom, whence uit extends outwardly and around a sheave2f1 of `the hoist block 23,v then upwardly and over a` sheave 25 carried at the outer end of the boom 19 and then around the drum 20 to which the free "i end ofthe cable Iis suitably attached. The construction thus far 'described is well known in the art and since it forms no part of this invention, it is believed: that a' fur? ther illustration and detailed `description thereof is unnecessary.

In cranes of this type yit/is desirable to employ mechanism for automaticallylimiting ,the tension the boom lift while working in certain predetermined areas, thereby preventing overba-lancing of the apparatus due to excessive loading in those areas, Thisv mechanism may comprise a tension device 30l (Figs. '3 and a) which. operates a suitable limit switch 31 controlling `an electrical operating circuit 32 (Fig. 6). The

devicel 30 Vcomprises a substantially cup shaped casting ethaving a central aperture 35 in its base 36 within which is slidably capacity in` those areas wherein it is safe to journaled a bar 37. Attached to one end of permit loading to full ca acity. This mechthe bar 37 at. right angles thereto is a disk anism vcomprises a suita le limit switch 60 member 38 which fits loosely within the connected in the operating circuit 32 in parcasting 34. The opposite end 39 of the bar allel with the limit switch 31 and operated 37 extends outwardly beyond the base 36 by'mechanism, hereinafter described, to conand has attached at right angles thereto a trol theoperating circuit 32 in accordance bar 40 which is adapted to operate the limit with the angular position of the boom in a switch 31 by engaginga pivoted arm 41 horizontal plane relative to the rails.

thereof. Disposed between the disk mem- As shown in Fig. 5, the platform 14 is ber 38 and the inner face of the base 36 are substantially. circular in construction7 hav a plurality of compression springs 42, 42 ing apair of diametrically opposed portions which normally urge the bai1 37 inwardly, 61 of larger radius than a pair of similarly in which position the bar 40 is disengaged opposed portions 62. The peripheral surfrom the arm 41 and the limit switch 31 is faces of these portions constitute a continu-` closed thereby maintaining the voperating ous cam surface which is constantly engaged the end 39 of the bar 37 circuit 32 closed. The device 30 is designedby a roller 63 rotatably carried at one end of so that-it automatically operates the limit a bar 64. The bar 64 -is slidably supported switch 31 as soon as the tension in the boom in bearings 65 andl 66 formed at opposite lift reaches some predetermined safe figure. ends of a housing 67, Which housing is suit- Formed on\`the casting 34 at the end oppoably secured on the under side of the cab 15.

site the base 36 are a pair of lugs 45, 45 Formed on the bar 64 intermediate its ends having apertures 46, 46

by means of which are a plurality of lugs 68, 68 which project t-he tension device 30 is ivotally secured to outwardly substantially at right angles to a lug 48 rigidly secured) to'the top of the the/bar. Interposed between the lugs 68 mast 18. Pivotally connected, at one end, to and one end 69 of the housing 67 are a pluis a bar 50 which rality of compression springs 70 which norcarries at its opposite end a`rotatable sheave mally urge the bar 64 outwardly towards 5l. A suitable cable,"52 is fastened to the the platform 14, therebyinsuring that the bar 50 as indicated at 53 (Fig. l) whence it roller 63 is constantly in engagement with g passes around one of a-pair of ,rotatable the periphery thereof. f

sheaves 54, 54 carried by a sheave block 55 The end of the bar 64 projecting through then around the sheave 51, and back around the bearing 66 is adapted to open the limit the second sheavev 54, whence it is taken up switch 60 by engaging a. pivoted arm 72 by a suitable winding drum (not shown) thereof (Fig. )5) when the roller 63 engages mounted in the cab 15. Fastened at one end either of the seetions61 of the platform 14. to the sheave block 55 `is a suitable cable 57 The platform 14 is so disposed fwith respect which is fastened at itsfo positie end to the to the rails 12 that the roller 63 engages one head of the boom 19,' as in icated at 58. of the sections 61 thereof when the -boom is Referring to Fig. 2,r the dotted lines l10.0 operating in the zones C and D, the sectionsv and 101, intersecting at the center or theo- 62 of the platform being engaged by the retical pivot point of lthe crane, divide the roller when the boom is operated in the zones workingarea thereof our four working zones A and B. indicated by letters A, B, C and D, respecy The operation of the above described tively.` vIt is obvious that the crane may mechanism is as follows: The tension device safely handle heavier loads in the areas A 30 is so designed that it automatically opens and with the boom parallel or at a' small theflimi't switch 31 when the tension inthe angleto the rails than in the areas C and D boom lift reaches some predetermined figure,

when the v'boom l1s at ri ht angles or at ani-willich is. determined \by the safe loading pom arat-ively large angle to the rails. It ,capacity of the crane with the boom operatlst erefore necessary t at the tension de- -ing in the zones C and D. With the boom` vice 30 be designed so as to actuate the limit operating in the zones A and B the crane switch 31 when the tension m the 'boom lift is permitted tov handle heavier loads to the reaches apredeterfnined limit in accordance extent of its ,full capacity since the operating nC and D.

the /provision of mechanism .whereby the ating circuit is maintained 'closed crane may be operated at substantially full either or both switches so that'` if the tension with the safe working capacity o the crane circuit is maintained closed through the under operating conditions in te areas' Cv limit 'switch' 60 which is controlled by the and D. Such an arrangement ,by itself angular position of the boom with respect to would, however, unnecessarily'limit the perthe. rails. As' the boom moves into' Ieither missible loading of the crane in the areas A of the zones C and D thelimit switch 60v is and B whereinthe crane may be operated automatically opened through the Iglatform safely atl a greater capacity than in the areasv cam 14, ashereinbefore described. owever,

' since the limit switches 31 and' 60 arecon- An important feature of this invention is nected in parallel with one another thleroperi-1 t oug Lemaire device 30 opens the limit switch 31 when the. crane is operating in either of the areas A or B, the operating circuit will be maintained through the platform cam switch 60. Alternatively in the areas C and D the platform cam switch is open which places the entire control of the operating circuit in the switch 81. A non-locking push button switch Z is connected in the operating circuit 32 in f parallel with the limit switches 31 and 60 and serves as a means whereby the operator may move the boom into a safe zone should the limit switch 8l be opened by excessive loading in the zones C and D.

Although the invention, as herein illustrated and described, ist particularly well adapted for use in connection with electrically operated locomotive cranes, it should be understood that it is not limited thereto and that. modications may be made without departing from the scope of the invention as dened in the appended claims.

1What is claimed is:

1. ln a crane, the combination with a rotatable boom; of means including a cani member rotated by the boom and means trolling the e'ectiveness of the tension re*- electrical circuit for operating the boom, of

means controlled by the load carried by the boom for controlling said circuit, and means operated by the rotation of the boom for controlling the edectiveness of said circuit controlling means.

1l. ln a crane, the combination with a rotatable boom and means including an electricalcircuit for operating the boom, of a plurality of means cooperating to control said circuit, means controlled by the load carried by the boom for operating one of said circuit controlling means, and means controlled by the rotation of the boom for operating another of said circuit controlling means. I

5., ln a crane, the combination with .a rotatable boom and means including an electrical circuit for 'operating the boom, of a plurality of switches connected in parallel with one another and cooperating to .control said operating circuit, a tension device actuated by the load carried by the boom for controlling one of said circuit controlling switches, and a cam rotatable with the boom for controlling another of said circuit controlling switches.1

In witness whereof, l hereunto subscribe my name this third day of July` A. D., 1925.

i CLAUDE THEODORE SIEBS. 

